扁枝石松屬

Holub in Preslia 47: 104. 1975; Ching in Acta Phytotax. Sinica 16(3): 7. 1978, et in Acta Bot. Yunnan. 3(1): 4. 1981 et 4(2): 127. 1982 (#$#Diaphastrum#$#, #$#Diaphasiastrum#$#) ; Fl. Xizang. 1: 14. 1983; Dixit, Census Ind. Pterid. 10. 1984, et Lycop. Ind. 83. 1988: Fl. Intramong. 1: 51. 1985; H. S. Kung, Fl. Sichuan. 6: 50. 1988; J. Z. Wang in Journ. Hebei Forest. coil. 5(2): 116. 1990; B. Ollg. Index Lycop. 6. 1989: Bir et al. in Ind. Fern J. 6: 33. 1989; S. H. Wu et Ching, Fam. Gen. Pterid. Sin. 107. 1991: S. H. Wu, J. N. Zhu et C. Y. Yang, Dict. Extant & Fossil Fam. Gen. Chin. Ferns 37. 1992; Fl. Xinjiang 1: 5. 1992; Fl. Jiangxi 1: 21. 1993; Fl. Zhejiang 1: 5. 1993; L. B. Zhang et H. S. Kung inActa Phytotax. Sin. 38(3): 272. 2000. —— Lycopodium Subgen. Complanatostachys Herter in Bot. Engl. Jahrb. 43: Beibl. 98: 29. 1909. P. P. —— Lycopodium Subgen. Thujophyllium Boerner, Fl. Deut. Volk. 110. 1012. —— Lycopodium Subgen. Lycopodium Sect. Complanata Victorin in Contr. Lab. Bot. Univ. Montreal 3: 34, 89. 1925; Wilce in Beih. Nova Hedwigia 19: 1-233. 1965: De Vol in H. L. Li, Fl. Taiwan 1: 38. 1975. —— Diphasium Presl ex Rothm. Ser.Complanata Rothm. in Fedde, Repert. Sp. Nov. 54: 64. 1944; U. Sen et T. Sen in Fern Gaz. 11(6): 423. 1978. —— Lycopodium sensu J. C. Tsai et W. C. Shieh in T. C. Huang, Fl. Taiwan ed. 2, 1: 29. 1994. p. p.

小型至中型土生蕨類，主莖伸長呈匍匐狀。側枝近直立，多回不等位二叉分枝，小枝扁平或為扁壓狀。葉螺旋狀排列或4行排列，密集，三角形或鉆形，基部貼生在枝上，下延，無柄，先端尖銳，略內(nèi)彎，邊緣全緣，中脈不明顯，厚草質或革質。孢子囊穗生于孢子枝頂端，圓柱形，淡黃色；孢子葉寬卵形，覆瓦狀排列，先端急尖，尾狀，邊緣膜質，具不規(guī)則鋸齒；孢子囊生于孢子葉腋，內(nèi)藏，圓腎形，黃色。孢子四面球形，極面觀近圓形，赤道面觀扇形。染色體基數(shù) x＝23。

全屬約23種，主要分布于北半球溫帶和熱帶。我國有3種1變種。